In a classic episode of the Australian science program The Curiosity Show, host Dr. Deane Hutton demonstrates the incredible Ames Window illusion, an optical illusion that makes it appear as if a window is rotating back and forth. Hutton slowly broke down how the illusion works.
The first component relies on what’s generally understood to be a window, which the leads to the conclusion that the illusion is truly a window. Yet, all is not as it appears to be. Much of the illusion is about on painted shadows a trapezoidal piece of cardboard spinning on a turntable.
In fact you’re looking at an optical illusion that was invented by Adelbert Ames back in 1951 and it’s quite a remarkable illusion. If we stop the window now you’ll notice that it was rotating the same direction, all the time on a turntable. The same way all the time, but it isn’t a rectangle. you assumed that it was a window so it must be a rectangle. Look at that end there – quite short this end quite large in fact. It’s a trapezoid, a strange shape. Not a rectangle though but because we’ve seen so many windows in our lives, we assume that they’re all rectangular.